Sublinear scaling for time-dependent stochastic density functional theory


Gao, Y. ; Neuhauser, D. ; Baer, R. ; Rabani, E. Sublinear scaling for time-dependent stochastic density functional theory. J. Chem. Phys. 2015, 142, 034106.
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A stochastic approach to time-dependent density functional theory is developed for computing the absorption cross section and the random phase approximation (RPA) correlation energy. The core idea of the approach involves time-propagation of a small set of stochastic orbitals which are first projected on the occupied space and then propagated in time according to the time-dependent Kohn-Sham equations. The evolving electron density is exactly represented when the number of random orbitals is infinite, but even a small number ( 16) of such orbitals is enough to obtain meaningful results for absorption spectrum and the RPA correlation energy per electron. We implement the approach for silicon nanocrystals using real-space grids and find that the overall scaling of the algorithm is sublinear with computational time and memory.



Last updated on 12/01/2017